DUSHANBE -- Tajikistan's Sambo Wrestling Federation says its athletes will not attend the world championships in South Korea next month because they were refused entry visas.

The federation cited South Korean sambo officials as saying that visa requests from the members of the Tajik national sambo team had been rejected because several Tajik wrestlers who took part in a tournament in South Korea in 2016 never returned to Tajikistan and stayed in the country illegally.

Tajik national team head coach Nosir Bozorov told RFE/RL on October 15 that at the heart of the issue are four Tajik wrestlers who participated in an international competition in South Korea and subsequently failed to return home.

Officials at the South Korean Embassy in Dushanbe refused to comment on the issue, saying that the information regarding visa refusal can be given only to individuals who requested such visas.

The World Sambo Championship will take place in the city of Cheongju from November 8 to November 10.

Sambo was developed in the Soviet Union and is a Russian acronym that stands for 'self-defense without weapons.'

Its main founder, Vasily Oshchepkov, died in prison as a result of dictator Josef Stalin's purge campaign in the 1930s after being accused of being a Japanese spy.

Many Tajiks have been trying to enter South Korea in recent years to stay there as migrant workers.